Background: Coronary stenting in acute myocardial infarction (AMI) is associated with a very low adverse event rate when performed at selected centers in clinical trials. However, because of exclusion criteria, a low-risk population is usually selected, while potential benefits of stenting should be investigated in an unselected population, including a larger proportion of high-risk patients.
Methods: We analyzed results obtained in 120 consecutive high-risk patients (mean age, 64 years; range, 38-95 years; 76% male), so defined according to the presence of 1 of the following: age > 75 years; Killip class 3; cardiogenic shock; 3-vessel or left main disease; ejection fraction < 45%; anterior AMI; previous bypass surgery; and/or out-of-hospital cardiac arrest. A primary procedure was performed in 63 patients and a rescue procedure in 57 patients. Stenting was attempted in all patients in which coronary occlusion could be crossed with the guidewire (117/120) and was successful in 115/117 (98%).
Results: Procedural success (TIMI 3 flow and residual stenosis < 20%) was obtained in 105 patients (88%), while a suboptimal result (TIMI 2 flow) was achieved in 9 patients (8%). At 30 days, twenty patients had died (17% mortality). For patients non in cardiogenic shock, 30-day mortality was 3.2%. At multivariate analysis, cardiogenic shock (p < 0.0001), peak CK-MB mass (p = 0.01), and suboptimal result (p = 0.018) were significant independent predictors of 30-day mortality. Rescue procedures were associated with a significant protective effect with respect to mortality (p = 0.033).
Conclusion: In our series, high-risk patients treated with percutaneous intervention for AMI had a very high mortality rate in the presence of cardiogenic shock, despite the use of stents, intra-aortic balloon pumping and abciximab. In the remaining patients, acceptable results were obtained even in the presence of 1 or more risk factors. Rescue stenting does not seem to be associated with increased risk compared to primary stenting.